Method of producing bulged containers



April 14, 1953 D. G. MAGILL EI'AL 2,634,563

METHOD OF PRODUCING BULGED CONTAINERS Original Filed Feb. 12, 1946 2SHEETS--SHEET l 1 K Z7 11 INVENTORS DO/VALO MiG/1L Ema/420 P. 8/665? 26MA an April 1953 D. e. MAGlLL ET AL 2,634,563

METHOD OF PRODUCING BULGED CONTAINERS Original Filed Feb. 12, 1946 2SHEETSSHEET 2 17 a n n mg INVENTORS Patented Apr. 14, 1953 METHOD OFPRODUCING BULGED CDNTAINERS Donald G. Magill, Great Neck, N. Y., andRichard P. Bigger, Stanton, N. J assignors to American Can Company, NewYork, N. Y., a corporation of New Jersey Original application February12, 1946, Serial No. 647,132, now Patent No. 2,561,391, dated July 24,1951. Divided and this application December 13, 1950, Serial No. 200,658

3 Claims.

The present invention relates to a method of producing containers forfrozen food products and has particular reference to producing asemirigid form of container having bulged side walls which facilitatethe freezing of the product in the container and which inventionprovides a unitary package which can be automatically filled and sealedand utilized for marketing and satisfactorily protecting the product.

This is a division of our United States patent application Serial No.647,132, filed February 12, 1946, on Frozen Food Container which issuedas Patent No. 2,561,391, dated July 24, 1951.

In some methods of quick freezing food products in containers anessential step of the method is intimate contact of the container wallswith portions of the freezing apparatus so that absorption of the heatfrom the product may be rapidly effected. This transfer of heat must beeffected through the walls of the container and through any otherintervening walls or layers such as inner liners, outer wrappers,labels, etc. For best results it has been found that more rapid and moreefficient freezing can be obtained when these intervening walls arereduced to a minimum as regards thickness or number of layers consistentwith adequate product protection and are arranged for firm contact withthe freezing apparatus.

The instant invention contemplates overcoming the difliculties anddisadvantages of prior containers by the provision of a container ofsemirigid construction in which liners and wrappers are eliminated sothat only a single flexible wall intervenes between the food product tobe frozen and the freezing apparatus.

An object of the invention is the provision of a method of producing acontainer for frozen foods wherein the container is a complete unitarypackage, without the use of inner liners or bags or outer wrappers orlabels, and which may be printed at the place of manufacture and whicheliminates the usual setting up or assembly of a number of separateparts prior to filling and sealing.

Another object is the provision of a method of producing such acontainer wherein the side walls of the container are bulged outwardlyand are flexible and are adapted to yield under pressure of a freezingapparatus to insure firm contact with the apparatus during the freezingoperation for the rapid and efficient transfer of heat through thewallof the container to eliect complete and rapid freezing of theenclosed product.

Another object is the provision of a method of producing such acontainer wherein the bulging 2 of the side walls of the container iseffected by the application of the end members to the body of thecontainer. 4

Another object is the provision of a method of producing such acontainer wherein the end wall dimensions of the container closuremembers are made relatively shorter than the end wall dimensions of thecontainer body and the marginal edge portions of the side walls of thecontainer body are forced inwardly to fit the closure members when theclosure members are applied to the body and clinched in place, toproduce a bidirectional yieldable or flexible bulge in the containerside walls extending from one closure member to the other and from onecorner of the body to the other, so that the bulged opposed side wallsprovide an intermediate cross-sectional container body dimension of amaterially greater area than the corresponding over-all dimensionoftheolosure members.

Numerous other objects and advantages of the invention will be apparentas it is better understood from the following description, which, takenin connection with the accompanying drawings, discloses a preferredembodiment thereof.

Referring to the drawings:

Figure 1 is a perspective view of a container made in accordance withthe method steps of the instant invention;

Fig. 2 is a side elevation of the container shown in Fig. 1;

Fig. 3 is an end elevation of the container;

Fig. 4 is an enlarged sectional view of the container takensubstantially along the line 4-4 in Fig. 2, with parts broken away;

Fig. 5 is an enlarged sectional view of one corner of the containershowing how the end members of the container are secured in place, theview also showing principal parts in section of an apparatus forperforming this closing operation;

Fig. 6 is a transverse section taken substantially along the line 66 inFig. 2; and

Fig. 7 is a perspective view of a flat blank from which the containerbody is made.

As a preferred embodiment of the invention the drawings illustrate amethod of making a rectangular shaped, semirigid container H for frozenfood products. Such a container includes a tubular fibre body I2 ofrectangular cross-section having broad or wide side walls l4 andcomparatively narrow end wal1sl5, the end walls being approximately onehalf the width of the side walls. A lap type side seam I6 is disposed inone of the end walls IS. The corner of the body are rounded and arepreferably i e-enforced by a plurality of closely spaced and parallelvertically disposed corrugationspbeads or scores 1-7. Thesecorrugations, beads or scores provide a corner radius and facilitate theassembly of the end members to the container body. They also provide ameans for taking up or absorbing the excess material produced by theflattening of the'bulged sidewalls,

especially during the plate type freezing operation.

All surfaces of the body including its edges preferably are impregnatedwith and/or carry a surface coating or film of a suitable liquid andmoisture vapor proofing substanceto protect the frozen product contentsof'theicontaineragainst' leakage and dehydration. .Insome cases eitherthe inner or outer surface only of the body-may carry a film or layer ofthe coating substance.

Suitable coating materials for this type of container are for example:hydrocarbon waxes of mineral-origin, or wax-like materials "ofvegetablebr animalorigin, with or without suitable modifiers; natural orsynthetic resins with or without suitable modifiers, and/or natural or,

synthetic rubber derivatives with or without suitable modifiers; or anycombination of the foregoing.

, The open ends of the fibre body [2 are closed with rectangular shapedmetal top and bottom.

end members 21. These end members are formed "with a countersunk panelwall 22 which merges I into'a surrounding or peripheral uprightfriction'orcountersink wall section 23. The friction the walls thatrenders them yieldable and flexible to insure firm contact of the majorpart of the "surface of the side walls with *thefreezing apparatusduringtheireezingof the product enclosed in the container and alsoefiectively insures intimate contact between juxtaposed container walls.

As analternative manner of securing the end members 2! to the ends ofthe fibre body both one of the end members may be readily cut throughwith a knife to remove the end member. 'In either case, a full openmouth 'is provided by the removal of the end member. By

' means of this full open mouth the frozen contents may be easilyremoved as a unit if desired. Also, since the container is liquid-proofand free oi any inner liners and outer wrappers the frozen product maybe readily thawed out in the container before opening.

In accordance with "the method steps of prod .cing such asemirig'idcontainer for frozen food products, the fibre body I? is first provided."This or countersink wall section initially fits loosely i withintheendof the body and engages against the inner surface thereof when theend member isifinally securedto the body. Adjacent the outer edge ,of,the body the countersink wall section 23 extends "outwardly over theedge, providing a gasket receiving ,channel and terminates .in aperipheral flange 26 which extends down against f theJoutside ofthe bodyand is crimped tightly "in place. v

The terminal edge of the flange 2' 3 is fformed with an'inwardlyextending edge curl or *hem" I which is imbedded oripressed'intothe'outersurffa'ce ofthefibre body walls. Thus the :upright --wall section23 andthe 'crimped flange 2d set off a peripheral channel .26 whichseals'the outer "coated edges of the body and provides an end seam, 2'!which is liquid tight and substantially moisture vapor proof. Wheretheinner surfaces only'of the body are liquid "and substantiallymoisture vapor proofed a lining compound 28 may be used in the channel254:0 seal the edges of the body. Or this lining compound 28 may be usedas an additional sealing medium even in cases where-allparts of thefibre body have first been liquid-moored and substantially moisturevapor proofed.

, The width of the end members 2! is preferably slightly smaller thanthe width of the inside of the body l2. With such an end member secured'to the body the outer periphery of the end seams 21, along the-narrowend walls 15 of the body is substantially flush with the body end wallsas *bes'tshown in Fig. 2. Theseend wallsare straight 7 from top tobottom. Along the wider side walls M, the end membersdraw the'body wallinwardly j-atthe end seams and thus impart a curved or *bellied effecttothese side walls in two directions, e.,along both the width and heightof the walls, asfbest shown in 'Figs. 3 and 4. The end seams j alongthese walls are therefore setback, inward *ly'ofthe"bodywalls; Itis thiscurved efiect in body preferably is made from a single fiat b'l'an (Fig.7') of suitable paper board.

Examples of such suitable paper board are sulphate or sulphite boards,or combinations of these with ground wood pulp.

In order to provide a container-which is completely sanitary it ispreferred to make the'paper board from all-virgin pulp, both the pulpand the board being produced under bacteriologically -controlledconditions.

' corners of the blank'a'djacent'this edgeare-preferably formed withtapered notches "33 for the side seams. At spaced intervals along theblank,

the re-enforcing beads or corrugations I! are formed therein extendingtransversely "thereof and setting on" the side and end walls l4, i5

for the body and re-enforcing therounded corners of the finished body.Such a blank ispref- "er-ably folded over a mandrel, horn "or otherforming device and its transverse terminal edges brought together inoverlapping relation'and secured together under pressure by the adhesive"32 to provide the body I? having the side seam Hi.

The formed body l2 may then be immersed in a bath of one of the coatingmaterials hereinbefore mentioned. This immersion of the body impregnatesit with the coating material and supplies a surface film of the coatingmaterial on all surfaces including its edges. In some cases where it isdesirable to keep the outer surface free of the coating substance, theinner surfaces-only may be sprayed-or otherwise covered with the coatingsubstance to liquid-proof and substantially moisture vapor proof thebody.

a In other cases, it may be desirable to coat either the inner, orouter, or both surfaces of the material from which the body is madewhilethe material is in the flat, or these surfaces may be coated byspraying or otherwise While still on the body making machine. .Afterdraining and/or drying the bodyis ready to receiveits end members 21.

aeasucs The bottom end member 2| is preferably first secured to the bodyIt. The resulting container is then filled with the product to be frozenor which may be pre-frozen, preferably without the use of any linersheets or bags. This filling of the container may be effectedautomatically at high speed in the usual filling machines used for suchpurposes. After this filling operation the top end member 2! is securedin place on the filled container. This seals the container and rendersit ready for introduction into the freezing apparatus for the freezingof the enclosed product.

In one form of a typical freezing apparatus the filled and sealedcontainers are placed between plates in which a refrigerant iscirculated. These plates are pressed against the side walls of thecontainers with a hydraulic ram to insure rapid and efficient transferof heat from the product within the containers to efiect the freezing ofthe product. It is for this purpose that at least the side walls 14 ofthe container are bellied outwardly in two directions so that fiexure ofthe side walls and a resulting firm contact of the freezing plates withthe major portion of the wall surface of these fibre side walls,outwardly from the rigid metal edges of the opposite end seams 21, willbe insured when such relatively flat plates are pressed against thecontainers.

This bellying of the container side walls [4 is brought about by theoperation of applying the end members 2| to the ends of the body l2. Forthis purpose the width of the bodies is'made slightly larger than thewidth of the end members to be secured to them as hereinbeforementioned. Preferably the length of the end members is substantially thesame as the length of the inside cross-sectional dimension of the body.

Thus when an end member is placed upon the end of the body the frictionwall 23 thereof will snugly engage the inside of the narrow end walls l5of the body and will loosely engage or remain inwardly spaced from thewider side walls [4 as shown in Fig. 5. With the body in this position achuck 46 is inserted in the countersunk panel of the end member to backup its friction wall 23. The end member flange 24 is then forcedinwardly against the outer surface of the body. As the flange 24 is bentinto place it carries the marginal edge portion of the body along theside walls l4 inwardly with it and clamps it tightly against thebacked-up friction wall 23 of the end member to form the clinched orcrimped end seam 21. This bending action preferably is performed by aset of squeezer laws 4'! which surround the end of the container beingoperated upon and which together with the chuck 46 may form parts of amore elaborate machine conventionally used for this purpose.

This bending of the flange 24 into seam forming position bellies out theside walls I4 in a gradually curved section extending from one endmember to the other. Transversely of the side walls the bellying actionbends the side walls outwardly in a gradually curved section extendingfrom one re-enforced corner to the other. Thus the entire outer wallsurface of the two side walls I4 is formed as a flexible and yieldableconvex or slightly dome shaped structure which provides firm contact ofthe entire wall surface of these side walls with the freezing apparatusduring the freezing operation.

During the end seam forming and container closing operation, the narrowend walls [5 of the body resist any bellying of these walls and thus thelatter remain straight. This is brought about by the snug fit of the endmember friction wall 23 between the end walls l5 of the body when theend seams 21 are formed. The seams are thus maintained substantiallyflush with the outer surfaces of these relatively narrow end walls.

As previously pointed out, in some desired cases, both the width and thelength dimension of the end members may be made slightly shorter thanthe corresponding dimensions of the body. This does not interferewiththe end seam crimping operation but results in both side and endWalls being outwardly curved or bowed.

While fibre stock for thecontainer body and metal stock for thecontainer ends have preferably been. mentioned herein; it is of courseun-- derstood that the scope of the invention includes other suitablematerials. For example, the complete container may consist entirely ofmetal or entirely of fibre, or a combination of suitable materials maybe used in its construction.

It is thought that the invention and many of its attendantadvantages-will be understood from the foregoing description, and itwill be apparent that various changes may be made in the steps of theprocess described and their order of accomplishment without departingfrom the spirit and scope of the invention or sacrificing all of itsmaterial advantages, the process hereinbefore described being merely apreferred embodiment thereof.

We claim:

1. The method of producing a semirigid container filled with acomestible to be frozen therein, comprising inserting the countersinkwall of a rectangular metallic end member into one end of a tubularrectangular fibre body having straight end walls and opposed straightside walls spaced apart a distance greater than the transverse dimensionof said end member countersink wall disposed therebetween, saidcountersink Wall having a laterally projecting peripheral flange,bending said end member flange inwardly against said body walls tosecure the end member thereto in a crimped seam thereby forcing saidopposed body side walls inwardly against said end member countersinkwall to reduce the space between said side walls adjacent said endmember, filling said body thus closed at one end with a comestible to befrozen, similarly inserting the countersink wall of a second identicalmetallic end member into the opposite end of said filled tubular bodywhile maintaining the same relative dimensional characteristicsaforesaid, and bending the second end member flange inwardly against thebody walls to secure the end member thereto in a crimped seam, therebysealing the container and similarly reducing the space between said bodyside walls adjacent said second seam and cooperating with said firstmemtioned seam and the container contents to impart to said body sidewalls a bi-directional flexible outward bulge extending between said endmembers and also extending between said straight body end walls, saidoutwardly bulged side walls being yieldable inwardly under externalpressure for insuring firm and intimate contact of the major surfaceportion of said opposed side walls with a freezing apparatus toeffectively freeze the contained comestible.

2. The method of producing a semirigid container for a comestible to befrozen therein, comprising inserting the countersink wall of arectangular metallic end member into one end of a a sence ftubular"rectangular fibre body having straight -end walls'and opposed straightside walls spaced apart 'a distance "greater than :the transversedimension of vsaid end member countersink wall disposed therebetween,said countersink wall hav- Zing a laterally projecting peripheral'fian'ge, bending said end member flange inwardly against ;said:bodywalls to secure the end member there- "to in'acrimped seam therebyforcing said opposed .body'side 'walls inwardly against said-end membercountersink wall to reduce the space between :said side walls adjacentsaid end member, similarly insertingthe countersink wall of a secondidentical metallic end member into the opposite :end of said filledtubular body while maintaining the same relativedimensional-characteristics aforesaid, and bending the second end member-fiange inwardlyagainst the body walls to secure the end member theretoin a crimped seam, thereby similarly reducing the space betweensaid'body sidewalls adjacent said second seam and cooperating with saidfirst mentioned seam to impart tosaid body side Walls an outward bulgeextending from one of said end members to the other, said outwardlybulged side walls being yieldable inwardly'under externalpressure forinsuring firm and intimate contact of the -major surface portion of saidopposed side walls with a freezing apparatus to effectively freeze acontained comestible.

3. A'method of producing a semirigid container for frozen food productswherein the products are frozen after filling in the container,comprising' the steps of providing -:a--.tubular fibre body ofrectangular cross-sectional configuration and providing metal endmembers for-said body, said end members each having asubstantiallyrectangular countersunk panelsurrounded by a countersink wallterminating in a laterally projecting peripheral flange, the distancebetween opposite sides of said countersink wall being less than thedistance-between opposite sides of said body in an initial looseassembly with saidbody,

and securing said end members to said body by J springing a pair of thebody walls adjacent opposite extremities of said body inwardly againstsaid countersink walls by bending said end member flanges inwardly andtightly against the outer peripheral surface of said body to secure saidend members :to said body and to provide an outwardly extended bulge inthe midportion .of

said body, whereby a food product filled within the container may berapidly frozen.

DONALD G. MAGILL. RICHARD .P. BIGGER.

References Cited in the file of this patent UNITED STATES PATENTS

